The present investigation analyses the efficacy of sanctions imposed by the European Union against third countries. It looks upon measures imposed after, or in force by 1992, year of the signing of the Treaty on European Union which created the Common Foreign and Security Policy (CFSP). Sanctions wielded within four legal frameworks are considered: CFSP sanctions, the suspension of development aid and trade preferences under the ACP-EU Partnership Agreement, the withdrawal of trade privileges under the Generalised System of Preferences (GSP), and other sanctions imposed by the EU outside these frameworks. Departing from the assumptions made by theories on the operation of sanctions, the study puts forward a series of hypotheses, which are subsequently tested with Qualitative Comparative Analysis (QCA) and empirical case-studies. After presenting some findings, the investigation concludes by assessing the relevance of traditional sanctions theory in accounting for the efficacy of EU sanctions, and the implications of the findings for the conceptualisation of the EU's international role.